Cathodochromic CRT projection display
AssigneeMassachusetts Institute of Technology
InventorLee T. Todd, Jr.
Life of this patent
Estimating the term…
Abstract
A cathode-ray tube projection system employing a cathodochromic image screen and electron beam erase and in which the image is projected from the image screen surface nearest the electron gun. The main advantages of this system are higher resolution and improved image erasure which provides a high-contrast image.
Claims20
A cathode ray tube system that comprises a cathode ray tube having cathodochromic image screen means, means for directing an electron beam upon the image screen means thereby to write an image upon the image screen means, and means for projecting the image from the image screen surface upon which the electron beam first impinges, said surface being the part of the image screen means that gets the hottest due to the impinging beam.
A cathodochromic cathode ray tube adapted to permit electron beam write and erase, that comprises:
- a cathodochromic image screen supported by a substrate;
- an anode;
- an electron gun acting to write upon the image screen and to erase the image screen, both writing and erasing being effected by direct transfer of energy from the electron beam to the image screen without significant heat loss to the substrate;
- and projection display means that comprises means for projecting an image from the image screen surface nearest the electron gun.
A cathodochromic cathode ray tube adapted to permit electron beam write and erase, that comprises, a cathodochromic image screen supported by a substrate;
- an anode;
- electron gun means that acts to write upon the image screen and to erase the image screen;
- and projection display means that comprises means for projecting an image from the image screen surface nearest the electron gun, said cathode ray tube having an electrically conductive substrate that forms part of the anode of the cathode ray tube and is sufficiently thick to support the image screen, a thermal insulating barrier upon the substrate, and a sensitized cathodochromic material layer supported by the thermal insulating barrier, the latter being the image screen of the cathode ray tube and being insulated from the conductive substrate by the thermal insulating layer.
A cathodochromic cathode ray tube adapted to permit electron beam write and erase, that comprises, a cathodochromic image screen;
- an anode;
- an electron gun acting to write upon the image screen and to erase the image screen;
- and projection display means that comprises means for projecting an image from the image screen surface nearest the electron gun;
- said image screen being supported by a substrate, a thick thermal buffer layer of unsensitized particles disposed upon the substrate and an outer layer of fine sensitized particles forming the image screen that receives an electron beam from the electron gun to perform write and erase functions, electrons of said beam in their travel from the electron gun to the anode striking first the layer of sensitized particles, thereby dissipating most of the electron energy in said sensitized layer and focusing an image there.
Dependencies are inferred from the claim text.